Why didn't Wisconsinites opt to repeal the law Walker implemented rather than Walker himself?

As I’m sure you know, Governor Walker of Wisconsin won a resounding victory in his recall election last night, and beat the Democratic nominee by a pretty wide (electorally speaking) margin. This will no doubt be seen as a green light to conservatives nationwide to press forward with far right agendas similar to those that Walker has pursued in his time as governor. Most prominently the laws restricting state-worker-unions and making collective-bargaining (aka Union negotiating for wages together) illegal, whilst scaling back their benefits and wages.

I have to wonder why the left in Wisconsin decided to go after Walker directly though. Recall elections are generally a tough sell. Walker has been running ad’s propping himself up since Christmas, and his opponent (Tom Barrett) wasn’t even decided until barely 6 weeks ago. People are generally of the opinion that even though they may not agree with the guy in office, if he was legally/fairly elected he should be allowed to serve his term. As such I think many people voted for Walker, despite being ideologically opposed to him. This is evidenced by exit polls showing that as much as 20% of the voters voting for Walker plan to vote for (not just not vote for Romney) president Obama in the November presidential election. I don’t think it’s a stretch to say that Walker and Obama are nearly ideological opposites.

Here in Ohio, a very similar scenario took place. Governor Kasich, a conservative Republican with heavy out of state backing, was swept into office during the Tea Party revolution-elections of 2010. He used a Republican controlled state congress to push through legislation that was nearly identical to Walker’s in Wisconsin, eliminating collective bargaining rights for state-worker-unions and scaling back their benefits/wages. People in Ohio were outraged and protested, only not in as great of numbers as those in Wisconsin did. But rather than attempt to recall governor Kasich, the left in Ohio instead opted to put a repeal vote of the law on the ballot. If voters in Ohio voted by simple majority to overturn the law, it would be revoked despite it’s approval in the statehouse. Last November the law was overwhelmingly thrown out by the people of Ohio… and Governor Kasich was clearly humbled.

My question is, why didn’t the people of Wisconsin try some similar approach? Is there no way for them to put a repeal of a law on a ballot like you can in Ohio? It seems to me they went through way too much trouble to get this recall election, and then put a lackluster opponent up against Walker (and in an already uphill battle)... when they could’ve just challenged the law itself.